The association between upper gastrointestinal symptoms and delayed gastric emptying (GE) shows conflicting results. This study aimed to assess whether the symptoms of the Gastroparesis Cardinal Symptom Index (GCSI) and/or the scores were associated with the result of GE tests and whether they could predict delayed GE. Patients referred for suspected gastroparesis (GP) were included in a prospective database. Demographical data, medical history, and symptoms of the GCSI score were collected for each patient. A GE scintigraphy was then performed with a 4-hour recording. Delayed GE was defined as a retention rate ≥ 10% at 4 h. Among 243 patients included in this study, 110 patients (45%) had delayed GE. The mean age (49.9 vs. 41.3 years; p < 0.001) and weight loss (9.4 kg vs. 5.6 kg; p = 0.025) were significantly higher in patients with delayed GE. Patients with diabetes or a history of surgery had a higher prevalence of delayed GE (60% and 78%, respectively) than patients without comorbidity (17%; p < 0.001). The GCSI score was higher in patients with delayed GE (3.06 vs. 2.80; p = 0.045), but no threshold was clinically relevant to discriminate between patients with normal and delayed GE. Only vomiting severity was significantly higher in patients with delayed GE (2.19 vs. 1.57; p = 0.01). GE testing should be considered when there are symptoms such as a higher weight loss, comorbidities (diabetes, and history of surgery associated with GP), and the presence of vomiting. Other symptoms and the GCSI score are not useful in predicting delayed GE.